The common version is the 1972 Brilliant Uncirculated silver Eisenhower Dollar (as depicted above) which came in the blue pack/envelope with a blue seal ('Blue Ikes').
There are two major versions of the 1972-S Eisenhower Dollar - both of them have a silver-clad composition with a 40% silver content.
What This Coin Looks Like (Obverse, Reverse, Mint Mark Location, Special Features, etc.):
